Metal Roof Mounting of Solar Pool Heaters

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A metal roof provides similar challenges for the installation of solar pool
heating panels as a rubber or one piece membrane roof. The main concern is
reducing the number of roof penetrations to minimize the risk of any
roof leaks over the life of the installation. One additional concern is the
crimp area in the roof which is raised above the roof surface which could
damage the solar panels. These obstacles are all overcome by constructing
a grid structure similar to a ground rack which is mounted on the roof
to support the panels, thus minimizing the number of roof mounting points
and keeping the panels above the roof surface, thus clearing any raised
obstacles.

Initially, 2" X 6" planks the same length as the solar panels are mounted
to the roof structure by fastening with lag bolts into the roof rafters, with
each penetration sealed with silicone sealant (left). The wide planks are used to
evenly distribute the weight of the support structure planks. The wide planks
also allow for an over abundance of sealant to be applied under the plank
where the lag bolt fastens the plank the the roof rafter.

The panel support 2" X 4" planks run the width of the solar panel array
(right) and are spaced every 15 inches to provide a stable backing for the solar pool
panels so that the panels can support winter snow loads without deformation
of the panels. This method also keeps the panels off the roof.

The solar panels are then mounted on the support structure (left) as they would in a
ground mount installation, strapped as necessary to provide adequate resistance
to wind loading.

The completed installation as viewed from the roof (right). Most of the support
structure is hidden from view by the solar pool panels, especially when
viewed from the ground.